The present inventive concept relates to the fabricating of photomasks and the like having fine patterns requiring high dimensional accuracy. In particular, the present inventive concept relates to an exposure system and to an exposure method of exposing a substrate to a charged-particle beam.
The manufacturing of electronic products typically includes a photolithography process. Photolithography is a lithography technique for forming a pattern, e.g., a circuit pattern, of a semiconductor device or the like. Photolithography includes an exposure process of transferring an image of a mask pattern of a photomask to a photoresist layer on a substrate. The exposed photoresist layer is then developed in a process that selectively removes (exposed or non-exposed) portions of the photoresist layer, thereby forming a photoresist pattern. An underlying layer(s) is then etched using the photoresist pattern as a mask. As a result, a pattern corresponding to the mask pattern is transcribed onto the substrate.
Accordingly, the accuracy of the mask pattern, such as accuracy of the positions of features of the mask pattern relative to one another, is a very critical factor in determining the product quality. The photomask is generally fabricated by an electron beam exposure system. In a conventional electron beam exposure system, a substrate is scanned by an electron beam to form the mask pattern.